REUTERS, COLOMBO- Sri Lankan troops killed 30 Tamil Tiger rebels in renewed fighting in the north of the island, officials said on Monday, as security was tightened in the capital ahead of a regional summit.

The government has dismissed a declaration by the Liberation Tigers of Tamil Eelam (LTTE) of a unilateral ceasefire from July 26 to August 4 as a goodwill gesture for a summit of South Asian countries.

The latest round of battles took place at the weekend in the districts of Jafna , Vavuniya, Polonnaruwa, Mannar and Mullaitivu.

"Troops have killed 30 LTTE terrorists in fighting on Saturday and Sunday," said a spokesman at the media centre for National security asking not to be named in line with the policy. Three soldiers were killed.

The Indian ocean island nation is on high alert with some 19,000 extra police and soldiers deployed in Colombo for the South Asian Association of Regional Corporation (SAARC) summit.

The rebels have said they would be forced to take "defensive action" if the military continued to attack them despite their declaration of a brief truce.

The government is pursuing a strategy to gradually retake the Tiger's northern stronghold and win the 25-year civil war amidst an almost daily barrage of land, sea and air attacks in northern rebel-held territories.

The military earlier this month said that it had dealt a "fatal blow" to the Tamil Tigers, with the capture of the northwestern town of Vidattaltivu, the main base of the Tigers' sea wing and their logistics hub for the region.